The purpose of this study is to investigate the counting time in detail based on the results of eye movement. Subjects were requested to count rapidly and correctly the dots from 2 to 10 projected on a screen four several exposure time (0.5sec, 1sec, 2sec, without time limit), eye movement were recorded by means of electrooculography and ophthalmography. The results were as follow; 1) Number of dots from 2 to 4 were grasped immediately but number of dots from 5 to 10 were grasped by counting. These two grasping types were also explained by the number of saccadic movement. 2) Two different states of eye movement were observed in inspection time; one was the potential period of eye movement depending on the reaction time of eye movement and counting dots in the center of stimuli etc., another was the continuous period of eye movement of which time was mutually related to the number of dots. 3) In the detection of dots set in symmetrical array, a grasping of dots by pattern recognition is considered to take the place of a grasping by counting of dots. 4) In the condition of 0.5sec exposure time, different eye movement from other time conditions was observed.

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The purpose of the present study is to clarify relationship between configuration of objects and vision by a series of experiments and to built a model for estimation of counting time. Four subjects are instructed to counts dots projected onto a screen. Eye movements are measured by two methods: electrooculography and eye mark recorder. Using obtained results, a model is built to estimate time required to count dots. The model consists of a 6-stage, 3-branch tree structure. Validity of the model is discussed.

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In the measurement in general, especially in various precision measurements, the method in which the desired measurement is accomplished by making the scale line coincide with the center of the two parallel target lines (or double reticle lines) has been used conventionally. In this paper, following problems are discussed, what is the mechanism of the process through which a man make his judgment concerning the measurement when the coincidence method of double reticle lines is employed, and what is the optimum condition for maximizing the advantage of the coincidence method based on the double reticle lines. For this purpose, a series of experiments by using the psycho-physical approaches (the constant method) and the experiments using the simulator of the measurement with the microscope have been conducted under various conditions. As a result of these experiments, it has been clarified that (1) as for the coincidence with the double reticle lines, the threshold of coincidence is governed by the distance between the central scale line and the reticle line; (2) from (1) and the results of the experiments, it is desirable to reduce the gap between the central scale line and the reticle lines on both the left and right sides by adjusting the thickness of or the interval between the two reticle lines.

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A method for testing the sharpness has been developed as part of the program for developing the methods of the evaluations of the performances of various utility goods such as the kitchen knife. The Japanese people have been sensitive to the sharpness of the kitchen knives, but measuring the sharpness in terms of its mechanical characteristics has not been the common practice until recently. In this paper, the sensory test of the sharpness, the measurement of the mechanical sharpness and the measurement of the mechanical characteristics of kitchen knives are done, and the relationships between the sensory sharpness, the mechanical sharpness, and the mechanical characteristics are considered. According to the results of these experiments; (1) the image of the sharpness is affected by two factors, (2) this result is in approximate agreement with two factors of the sensory sharpness determined by the multidimensional scaling, (3) the sensory sharpness corresponds to two mechanical characteristics, (4) such mechanical characteristics can be determined as the forces required in cutting the sample with the kitchen knife when it is tested by the sharpness testing device, (5) change in the angle of the edge of the knife resulting from the progress of its degradation can be assumed to cause the change in the sensory sharpness, and (6) it has become possible to measure the sharpness of the kitchen knife by the mechanical means.

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